Screening apparatus



March 26, 1940. w. F. PIPER SCREENING APPARATUS Filed May '7, 1938 2 Sheets-Sheet l March 2 1940. Pm 2,194,721

SCREENING APPARATUS Filed May 7, 1938 2 Sheets-Sheet 2 Patented Mar. 26, 1940 STATES 2,194,721 SCREENING APPARATUS Walter 'F. Piper, Oak Park, Ill., assignor to The Beardsley & Piper Company, Chicago, Ill.,a

corporation of Illinois Application May 7, 1938, Serial No. 206,545 9 Claims, (Cl. 209-332) The present invention relates generally to screening apparatus. More particularly the invention relates to that type of apparatus which is designed or adapted for use in a foundry in connection with the screening of molding sand and comprises asubstantially horizontal frame, an inclined undulatory screen in the frame, and motor driven mechanism for rapidly gyrating the frame'and screen in such manner that the sand to be screened when brought into engagement with the screen is subjected to a hopping or jumping action whereby the small or fine particles are caused to pass through the screen and the larger particles are either broken up or together with any scrap or other foreign material are caused to'advance in step by step fashion to the lower or discharge end of the screen.

One object of the invention is to provide a screening apparatus of this type which is more rugged and durable than previously designed apparatus of the same general character and in addition is more efficient in operation and requires less servicing or attention as well as replacement of parts.

Another object of the invention is to provide a screening apparatus of the type and character under consideration in which the frame and screen are supported and held against rotation during gyration thereof by the motor driven mechanism by a plurality of posts which extend. substantially vertically and have the upper and lower ends thereof connected respectively to the screen-frame and a rigid base frame beneath the screen frame by way of mounting blocks of rubber or like resilient elastic material in order that they are free to tilt or swing laterally in connec-. tion with gyration of the screen frame and screen.

A further object of the invention is to provide a screening apparatus of the last mentioned character in which the mechanism for gyrating the screen frame and screen is mounted on and supported by'the base frame and comprises a rotatable motor driven head and in addition a rotatable self-aligning shaft which is carried in an eccentric position by the head and connected to the screen frame in such manner that during drive of the head by the motor it serves to efiect or produce the desired gyratory move.- ment or action of the screen frame and screen,

A still further object of the invention is to provide a sand screening apparatus which is'generall-y of new and improved construction and in which the various parts thereof are arranged compactly and are so constructed and positioned I one with respect'to the other that the apparatus as a whole is capable of withstanding hard usage and is not subjected to damaging strains or stresses. during operation.

Other objects of the invention and the various advantages and characteristics of the present screening apparatus will be apparent from a consideration of the following detailed description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly definedby claims at the conclusion hereof. i

In the drawings which accompany and form a part of thisspecification or disclosure and in which likenumerals of reference denote corresponding parts throughout the several views:

Figure 1 is an end view of a screening apparatus embodying the invention parts being broken away and shown in section in order better to illustrate or disclose the arrangement of the posts for supporting the screen frame'and screen and holdingthem against rotation during gyration thereof by the motor driven mechanism;

Figure 2'is a vertical longitudinal sectional view illustrating the cross-sectional construction of the screen frame and screen and showing in de-; tailthe arrangementand design of the motor driven gyrating mechanism;

Figure 3 is a vertical-transverse section taken on the line 3-3 of Figure 2 and illustrating the construction of the vertically extending supporting posts forthe screen frame and, the manner in which they are'connectedat the upper and lower ends thereof to the screen frame and the base frame respectively;

Figure i is an enlarged vertical sectional view through the motor driven head of the gyrating mechanism, showing in detail the manner in which theself-aligning eccentric shaft is carried by the head; and

Figure Sis a horizontal sectional view on the line 5-5 of Figure 4..

The screening device which isshown in the drawings constitutes thepreferred form ,or embodiment of the invention. It is essentially and primarily adaptedxfor use in a foundry or like establishmentin connection with the screening of {molding sand and as the main or'principal parts thereof comprises a screen frame 6, a screen 1', a base frame 8; and gyrating' mechanism 9;

The screen frame 6 is spaced above the base frame 8 and is rectangular. It is disposed at a slight inclinev or angle with respect to the horizontaland' comprises a pair of plate metal side walls It and a pair of plate metal end walls ll. The" side walls arefdispfosed in parallel relation 5 side and end walls.

horizontally and is disposed directly beneath the r and are suitably connected at the ends thereof to the ends of the end walls II. The upper portion of the end wall at the low end of the screen frame is bent outwardly into a substantially horizontal position and together with extensions [2 on the adjacent upper end portions of the side walls forms a discharge chute l3. The upper margins of the side walls and the other end wall are bent outwardly to form a reinforcing flange I l around the top of the screen frame. The frame 6 is additionally reinforced by a pair of vertically spaced angle iron frames l5 and I6. The frame It extends around the central portion of the screen frame and is welded or otherwise fixedly secured to the outer faces of the It extends substantially character or design and is marginally supported at the upper portion of the frame 6 by a rectangular angle iron'frame H. The latter is welded to the inner faces of the side and end walls of the screen frame and is inclined downwardly in the direction of the discharge chute I3.

The low end of the frame 17 is substantially flush or coplaner with the outwardly bent chute forming upper portion of the end wall at the low end of the screen frame 6, as shown in Figure 2. When the screen frame and screen are gyrated by the mechanism, as hereinafter described, the

sand to be screened is subjected to a jumping or hopping action when it encounters the screen 1 withv the result'that the small or fine particles pass through the screen and the screen frame and the larger particles are either broken up or are 9 the large particles of sand to be screened are subjected to a prolonged hopping or jumping action before they are finally discharged from the apparatus via the discharge chute l3. The screen 1 preferably rests loosely on the frame I! and hence may be readily removed for cleaning purposes or replacement.

The base frame 8 is adapted to rest upon any suitable'supporting structure, suchfor example, as the framework over a sand pit in the foundry in which the apparatus is employed. It is adapted to extend horizontally and comprises a pair of channel bar sides l8 anda pair of channel bar ends l9. The sides are arranged in parallel relation and are rigidlyconnected at the ends thereof to the end portions of the channel bar ends I9.

. outwardly of theside walls ll) of the screen frame.

In addition to'the channel bar sides and ends gyration thereby by the mechanism 9.

the base frame comprises a pair of channel bar cross-pieces 20. Those pieces overlie and extend across the central portions of the sides l8. They are spaced a small distance apart and have the ends thereof welded or otherwise rigidly secured to the central portions of the top flanges of the frame sides l8. The frame 8 supports at the sides thereof a plurality of upstanding posts 2|. These posts in turn support the frame 6 and screen i so that they are held against rotation during There are preferably four posts 2| and these are disposed two at one side of the two frames and two at the other side. The posts are adapted to swing or tilt laterally, as hereinafter described, in connection with gyration of the screen frame and screen and consist of elongated rods 22 and sleeves 23 around the central portions of the rods. The lower ends of the posts are associated with a plurality or set of inverted U-shaped brackets 24. The latter correspond in number to the posts and have the side pieces thereof Welded to the inner faces of the channel bar sides H! of the base frame 8. The lower ends of the rods 22 extend through enlarged holes 25 in the central portions of the cross-pieces of the brackets 24 and are surrounded by lower mounting blocks 26 and upper mounting blocks 21. Such blocks are formed of a rubber or like resilient elastic material. The lower blocks underlie and abut against the bottom faces of the cross-pieces of the brackets 24 and are clamped thereagainst by means of circular centrally apertured plates 28 and nuts 29. The plates 28 are mounted on the lower extremities of the rods 22 and rest upon the nuts 29 which, as shown in Figure 3, are connected to external screw threads on said lower extremities of the rods. The central portions of the plates 28 embody upwardly extending annular flanges 36 which fit within cylindrical sockets 3i in the bottom portions of the lower mounting blocks 26 and serve to prevent relative sidewise movement of the lower blocks and the rods 22. The upper mounting blocks 21 rest on the top faces of the cross-pieces of the inverted U-shaped brackets 24 and are urged or clamped downwardly thereagainst by way of circular centrally aper tured plates 32 on the lower ends of the sleeves 23. The central portions of the plates are welded or otherwise fixedly secured to the lower end of the sleeves and have depending annular flanges 33 which fit within cylinidrcal sockets 34 in the top portions of the upper mounting blocks 21 and serve to prevent relative sidewise displacement of said upper blocks and the posts 2i. Bushings 35 fit loosely within the holes 25 in the central portions of the cross-pieces of the brackets 24 and fit within cylindrical sockets in the blocks 26 and 27. They surround the lower ends of the rods 22 and coact with the annular flanges on the plates 28 and 32 to prevent lateral displacement of the blocks with respect to the lower ends of the posts. The upper ends of the posts are associated with a plurality or set of inverted U-shaped brackets 36. The latter correspond in number to the posts and fit between the side pieces of the rectangular frames l5 and I6 around the screen frame 6 and have the side pieces thereof welded to the outer faces of the side walls In of the screen frame. The upper ends of the rods 22 extend through holes 31 in the central portions of the cross-pieces of the brackets 36 and are surrounded by lower mounting blocks 38 and upper mounting blocks 39. Such blocks are formed of the same material as, and are similar 7 axis ofthe armature shaft and has an open upper in size and shape to, the mounting blocks 28am! 2? and fit respectively against the bottom and top faces of the crossepieces of the brackets 36. .The lower blocks 38 are clamped in place by means of circular centrally apertured plates 40 which surround and are welded to the upper ends of the sleeves 23 and have upstanding annular flanges M in cylindrical sockets 42 in the bottom portions of the lower blocks 38. The upper blocks 39 are urged downwards in clamped relation with the top face of the cross-pieces 36 by way of circular centrally apertured plates 43 and nuts at around the upper extremities of the rods 22. The nuts M are connected to external screw threads on the rods and the plates 43 have depending annular flanges 45 in cylindrical sockets B6 in the upper portions of the upper blocks 39. Bushings 42 are mounted on the upper ends of the rods 22 between the plates lil and 43 and fit loosely within the holes 31 in the central portions of the cross-pieces of the brackets 36. "I'hey project into cylindrical sockets in the contiguous portions of the lower and upper mounting blocks and together with the annular flanges 4| and 45 prevent lateral or sidewise displacement of said blocks til and 39 with respect tothe upper ends of the shaft. The nuts 29 and M are tightened so that clamping pressure is exerted against all of the mounting blocksi Because the blocks are formed of rubber or like material, they permit the post 22 to tilt or swing sidewise during gyration of the screen frame and screen in connection with operation or drive of the mechanism 9. As the result of the fact that the blocks are under clamping pressure they tend to return to an upright position. Because of the specific construction and mode of attachment the posts effectively and efficiently support the screen frame and screen and preclude rotation of the latter while at the same time they tilt readily in connection with gyratory action or movement which is encountered during drive of the mechanism 9. Due to the fact that rubber type mounting blocks are employed at the ends of the posts there are no parts which require lubrication and are subject to such wear that replacement at frequent intervals is necessary. 7

The gyrating mechanism 9 comprises an electric motor 48, a driving head 69, and an eccentric shaft iii). The electric motor is disposed between the channel bar cross-pieces 20 and embodies a vertically extending armature shaft 5! and a housing 52. The housing encases field windings for the armature and embodies a top cap 53. This cap, as shown in Figures 2 and 4, embodies outwardly extending lugs 56 which rest on the top flanges of the crosspieces 213 and are rigidly secured to such flanges by bolts" 55. The upper end of the armature shaft projects through the central portion of the cap 53 and is journaled in a roller bearing 56 which is housed within an annular upstanding integral flange 5! on said central portion of the cap. An enlarged disk- 58 is keyed or otherwise drivably connected to the portion of the upper end of the armature shaft which projects above the bearing 56 and this disk carries the driving head $9. The latter is provided with an annular bottom flange 59 and embodies in the top portion thereof a socket 60. Bolts El extend through the outer margin of the disk 58 and into the flange 59 and serve to secure the driving head and disk together so that the former is driven by the latter during operation of the electric motor 58. "I he socket fill is eccentrically disposed with respect to the end. The shaft 50 extends verticallyand is provided with a disk-like element 62 at its upper end. The lower end of the shaft 50 projects into the eccentrically disposed socket 60 and is journaled in a roller bearing 63. The latter com,- prises an inner race 64, an upper series of rollers 65, a lower series of rollers 5.6, and .a pair of outer races 67 and 6.8. The inner race is shrunk around or otherwise fixedly secured to the lower end of the shaft 50 and has a rounded outer face, as shown in Figure l. The upper series of rollers extend upwardly and inwardly and fit between the outer race Bl and the upper portion of the inner race 64. The lower series of rollers 66 extend downwardly and inwardly and fit between the inner portion of the outer race 68 and the lower portion of the inner race 66.

The outer race 61 for the upper series of rollers fits within and is carried by a screw cap 63a, which as shown in Figure 4. surrounds the eccentric shaft 50 and fits within the upper end of the socket 60. Because of the angular arrangement of the two series of rollers the bearing 63 acts as a thrust bearing whereby axial displacement or movement of the shaft GE! is precluded. Due to the fact that the outer face of the inner race 64 is rounded the shaft 51! is permitted to tilt to a comparatively small extent and in this respect is self-aligning. The bearing 63 is lubricated by means of a hollow stem 70. which is welded to and projects upwardly from the upper end of the shaft 58). This stem communicates with the interior of the socket 69 by way of a longitudinally extending duct H in the shaft and at its upper end has a fitting 2 for a grease gun or like lubricant applicator. A bushing 13 with a screw plug 14 surrounds the upper end of the stem 10 and serves as a protector for the fitting 12. As shown in Figures 1, 2 and 3, the stem iii extends through 'a hole in the central portion of the undulatory screen i and serves to hold the screen against longitudinal sliding movement relatively to the screen frame 6. In order to counterbalance the driving head '59 and the shaft 56 and the various parts which are associated therewith an arcuate counterweight i5 is provided. This weight is suitably secured to the upper portion of the driving head and is disposed diametrically opposite the eccentrically disposed socket 60. The disk-like element 62 overhangs the counterweight and is provided at the margin thereof with a depending cylindrical skirt it. This skirt is welded or otherwise drivably connected at its upper end to the element 62 and is of such length that it surrounds and houses the driving head 49, the disk 58,and the roller bearing 56, so that any sand passing downwardly through the screen frame ii is precluded from coming in contact therewith. During drive of the electric motor 9 the armature shaft operates, through the medium of the disk 58 to drive the driving head 39 and the latter in turn operates to gyrate the eccentric shaft 50 and the skirt 16. The gyratory movement or action is transmitted from the sleeve 16 to the screen frame 6 by way of a transversely extend ing member TI and a pair of longitudinally extending channel beams 18. The member 121 extends between and is welded. to. the side walls it of the screen frame t and consists of a pair of upwardly convergent deflector forming plates '59.

These plates are welded together along the upper' edges thereof and have in the central portions thereof substantially semicircular cut-outs '80 in which the skirt l6 fits. The edges of the plates which define the cut-outs are welded to the contiguous portions of the skirt so as to form a rigid or driving connection between the skirt and the member H. The lower ends of the plates overlie the cross-pieces 2B3, as shown in Figure 2, with the result that the screened sand after passing through the screen frame 6 is deflected toward the ends of the apparatus and cannot come in contact with the electric motor 49 of the gyrating mechanism 9; The channel beams l8 are positioned in parallel relation and midway between the side walls It of the frame 6 and extend between and are welded to the skirt #6 and the end walls ll of the screen frame 6. As a result of the arrangement or disposition of the members TI and the beams 18 the screen frame 6 is so connected to the skirt 16 that gyratory action is imparted from the latter to the former. Such action is in turn imparted by the frame to the screen i and the latter when sand is delivered onto it operates as hereinbefore described, to subject the sand to a hopping or jumping action and cause the small grains or particles to pass therethrough and the coarse particles and scrap to move in step by step manner to the discharge chute I3.

The operation of the apparatus is as follows: When it is desired to screen sand in order to condition it for use in molds, current is supplied to the electric motor 48. This causes the motor to operate and results in drive of the head 49. The latter, in turn, as previously pointed out, operates to gyrate the shaft 58 and through the medium of the disk-like element 52, the skirt I6 and the member l? and the beams 78 to gyrate correspondingly the screen frame and screen. When the sand to be screened is dumped or otherwise introduced onto the screen I, it is subjected to the aforementioned hopping or jumping action. During such action the fine particles pass through the screen and the larger particles together with the scrap work toward the low end of the screen and are eventually discharged via the chute I3. During gyration or gyratory action, the screen frame and screen are held against rotation by the action of the posts 22 which because of the action of the rubber mounting blocks limit the screen frame and screen to a gyratory action corresponding to the action of the shaft 50.

The herein described screening apparatus is extremely eihcient in operation and is durable and rugged as the result of the specific mounting of the screen frame 6. It involves a compact arrangement of parts and is capable of withstanding hard usage because of the elimination of damaging strains and stresses. By reason of the fact that the apparatus embodies the skirt l6 and the deflector forming plates 19 the driving parts are efficiently and effectively housed against contact with the screened sand.

Whereas the apparatus has been described as being primarily adapted for use in screening molding sand, it is to he understood that it can be used in connection with the screening of other granular materials. it is also to be understood that the invention is not to be restricted to the details set forth since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patentis:

1. A screening apparatus comprising in combination a frame provided with brackets and having a screen associated therewith, a base frame disposed beneath the screen frame and provided with brackets in alignment with the first mentioned brackets, means for supporting said screen frame so that it is free to gyrate comprising a plurality of upstanding rigid posts extending between the two frames and having the ends thereof extending loosely through holes in the brackets and provided with adjustable clamping means in spaced relation with respect to said brackets, and pairs of rubber blocks surrounding the ends of the posts and clamped against and in straddled relation with the brackets by said clamping means and serving so to connect the ends of the posts to said brackets that the posts are tiltable and tend to spring back into a normal substantially vertical position, and mechanism for gyrating the screen frame including an electric motor mounted on and disposed centrally of said base frame.

' 2. A screening apparatus comprising in combination a frame provided with brackets and having a screen associated therewith, a frame disposed in vertically spaced relation with the screen frame and provided with brackets in alignment with the first mentioned brackets, means for supporting said screen frame so that it is free to gyrate comprising a plurality of upstanding rigid posts extending between the two frames and having the ends thereof projecting loosely through holes in the brackets and provided with vertically adjustable clamping means and pairs of resilient mounting blocks surrounding the ends of the posts and clamped against and in straddled relations with the brackets by said clamping means and serving so to connect the ends of the posts to the brackets that the posts are tiltable and tend to spring back into a normal substantially vertical position, and means for gyrating the screen frame.

3. A screening apparatus comprising in combination a horizontally extending frame provided with outwardly projecting side brackets and having a screen associated therewith, a base frame disposed beneath the screen frame and provided with side brackets in alignment with the first mentioned brackets, means for supporting said screen frame so that it is free to gyrate comprising a plurality of upstanding posts extending between the two frames and having the ends thereof extending loosely through holes in the brackets and provided with vertically adjustable clamping plates and in straddled relation with said brackets, and pairs of resilient mounting blocks around the ends of the posts clamped in straddled relation against the brackets by the adjustable clamping plates and serving so to connect the ends of the posts to the brackets that the posts are tiltable to a limited extent and tend to spring back to a normal substantially vertical position, and mechanism mounted on the base frame for gyrating the screen frame.

4. A screening apparatus comprising in combination a substantially horizontally extending frame provided with brackets and having a screen associated therewith; a frame disposed in vertically spaced relation with the screen frame and provided with brackets in alignment with the first mentioned brackets; means for supporting said screen so that it is free to gyrate in a substantially horizontal plane comprising a plurality of upstanding posts extending between the two frames and consisting of rods having the ends thereof projecting loosely through holes in the brackets and provided at their outer extremities with vertically adjustable clamping plates in opposed and outwardly spaced relation with the brackets, and sleeves fitting around the central portions of the rods and having fixed clamping plates at the ends thereof in opposed and inwardly spaced relation with said brackets, and pairs of resilient mounting blocks surrounding the ends of the rods and clamped against and in straddled relation with the brackets by the clamping plates and serving so to connect the rods to the brackets that the posts are free to tilt to a limited extent and also tend to spring back into a normal substantially vertical position; and mechanism for gyrating the screen frame.

5. A screening apparatus comprising in combination a rectangular substantially horizontal frame provided with outwardly extending side brackets and having a screen associated therewith; a rectangular base frame disposed beneath the screen frame and provided with inwardly extending brackets in alignment with the first mentioned brackets; means for supporting said screen so'that it is free to gyrate in a substantially horizontal plane comprising a plurality of upstanding posts extending between the 'two frames and consisting of rods having the ends thereof projecting loosely through holes in the brackets and provided at their outer extremities with vertically adjustable clamping plates in opposed and outwardly spaced relation with the brackets and sleeves fitting around the central portions of the rods and having clamping plates at the ends thereof in opposed and inwardly spaced relation with said brackets, and pairs of resilient mounting blocks surrounding the ends of the rods and clamped against and in straddled relation with the brackets by the clamping plates and serving so to connect the rods to the brackets that the posts are free to tilt and also tend to spring back into a normal substantially vertical position; and mechanism for gyrating the screen frame including an electric motor mounted on and positioned centrally with respect to said base frame.

6. A screening apparatus comprising in combination a rectangular substantially horizontal frame and having a screen associated therewith, a base frame beneath the screen frame, means extending between the two frames for supporting the screen frame so that it is free to gyrate, and mechanism for gyrating the screen frame comprising an electric motor mounted on and centrally disposed with respect to the base frame and having a vertically extending armature shaft, a rotary head connected for drive by the upper end of the armature shaft, a rotatable vertically extending shaft carried eccentrically by the head and having fixed thereto a skirt surrounding the head, and structural members connected to and extending between the skirt and the screen frame.

7. In a screening apparatus of the character described, the combination of a rectangular substantially horizontal'frame having a screen associated therewith a base frame beneath the screen frame, means extending between the two frames for supporting the screen frame so that it is free to gyrate in a substantially horizontal plane, and mechanism for gyrating the screen frame comprising an electric motor mounted on the base frame and provided with an upwardly extending armature shaft, a rotary head connected to, and for direct drive by, the upper end of the armature shaft, a rotatable vertically extending shaft carried eccentrically by the head and having an enlarged disk-like element fixed to its upper end and in addition a skirt connected to and dependin from said element and extending around and forming a shield for the head and upper end of the armature shaft, and structural members between the skirt and the side and end members connected to and extending of the screen frame.

8. A screening apparatus comprising in combination, a rectangular substantially horizontal frame having a screen associated therewith and provided with an open bottom, a base frame beneath the screen frame, means extending between the two frames for supporting the screen frame so that it is free to gyrate, and mechanism for gyrating the screen frame comprising an electric motor mounted on and positioned centrally with respect to the base frame and having a vertically extending armature shaft, a rotary head connected for drive by the upper end of said shaft, a rotatable vertically extending shaft carried eccentrically by the head and having a skirt fixed thereto and surrounding the head, and an upward'y tapered structural member extending between and connected to the sides of the screen frame and having the central portion thereof provided with a hole for, and secured to, the skirt.

9. In a screening apparatus of the character described, the combination of arectangular substantially horizontal frame having a screen associated therewith, a base frame beneath the screen frame, means extending between the two frames for supporting the screen frame so that it is free to gyrate in a substantially horizontal plane, and mechanism for gyrating the screen frame comprising an electric motor mounted on the base frame and provided with an upwardly extending armature shaft, a rotary head connected to, and for direct drive by, the upper end of the armature shaft, a rotatable vertically extending shaft carried eccentrically by the head and having an-enlarged disk-like element fixed toits upper end and in addition a skirt connected to and depending from said element and extend ing around and forming a shield for the head and upper end of the armature shaft, and a structural member consisting of a pair of opposed upwardly convergent deflector forming plates having the upper margins thereof connected together and their end margins secured to the sides of the screen frame and having their central portion shaped to form a hole for and welded to the skirt.

, WALTER F. PIPER. 

